WHEN IT COMES TO EMOTIONAL LEARNING, the things you have heard may be affecting you as much as those you have experienced, according to Elizabeth A. Phelps, Ph.D., a New York University neuroscientist. Phelps and her colleagues at Yale University found that patients who expected to experience an electric shock suffered anxieties similar to those who had a response to a real threat. "A lot of our fears and anxieties are learned through communication," says Phelps. "If someone tells you to be afraid of a dog, then the brain responds as if you actually were."

During the study, published recently in Nature Neuroscience, subjects were shown a random sequence of blue and yellow squares and told that they might receive an electric shock when a blue square was shown. The study used magnetic resonance imaging (MRI) of the amygdala -- a section of the brain that processes stimuli into fear -- and electrodes hooked to the patient's fingers to monitor the responses to imagined threats. By comparing her results to the MRIs of people who had fear conditioned through experience, Phelps was able to show that a subject's brain responded as if the threat were real.

"We are trying to understand the neural basis of fear and anxiety," says Phelps. "If we continue to study imagined fears then we can treat things like panic anxiety and post-traumatic stress disorder." According to the National Institute of Mental Health, 19 million Americans suffer from anxiety disorders such as panic disorder, obsessive-compulsive disorder, post-traumatic stress disorder, phobias and generalized anxiety disorder. With so many people trying to cope with these afflictions, the potential benefit of this line of research is enormous. But until then, don't believe everything you're told.